r208128 - Include translation unit filename in global ctor symbol names.
Nico Weber
thakis at chromium.org
Tue May 6 15:43:49 PDT 2014
On Tue, May 6, 2014 at 3:39 PM, Alexey Samsonov <samsonov at google.com> wrote:
> Correct, _GLOBAL__I_a is hardcoded in ASan instrumentation pass. I'm not
> opposed to the change, just curious - what
> parts of ASan reports would you like to improve?
My motivation is unrelated to Asan – I'd like to know which files add
static initializers, because that makes it easier to remove static
initializers. Reid mentioned that he heard people mentioning that
people using Asan's init order feature complaining about the current
system not being obvious.
I can see two ways of fixing this:
1. Change createInitializerPoisonCalls to instead call
M.getGlobalVariable("llvm.global_ctors") and then add all the
functions in that array.
2. Change createInitializerPoisonCalls to walk all functions and look
for those that start with /_GLOBAL__(sub_)?I_/ and use the first of
them.
2 would be roughly what the code currently does, but 1 seems nicer.
What's better?
> Generally, there's at least
> __cxx_global_var_initN function in the report, which
> has the correct file name in the debug info.
>
>
> On Tue, May 6, 2014 at 3:35 PM, Nico Weber <thakis at chromium.org> wrote:
>>
>> Aha, lib/Transforms/Instrumentation/AddressSanitizer.cpp mentions
>> _GLOBAL__I_a (I only looked in compiler-rt so far, not llvm). Probably
>> easy to fix, giving it a shot…
>>
>> On Tue, May 6, 2014 at 3:21 PM, Nico Weber <thakis at chromium.org> wrote:
>> > Apparently this makes TestCases/Linux/initialization-bug-any-order.cc
>> > and TestCases/initialization-bug.cc unhappy. I looked at the asan code
>> > for this for a bit (and I'll continue looking). I don't understand yet
>> > why this is causing that failure. (+samsonov in case it's obvious to
>> > him.)
>> >
>> > On Tue, May 6, 2014 at 1:32 PM, Nico Weber <nicolasweber at gmx.de> wrote:
>> >> Author: nico
>> >> Date: Tue May 6 15:32:45 2014
>> >> New Revision: 208128
>> >>
>> >> URL: http://llvm.org/viewvc/llvm-project?rev=208128&view=rev
>> >> Log:
>> >> Include translation unit filename in global ctor symbol names.
>> >>
>> >> This makes it easier to see where a global ctor comes from, and it also
>> >> makes
>> >> ASan's init order analyzer output easier to understand. gcc does this
>> >> too,
>> >> but only in -fPIC mode for some reason. Don't do this for constructors
>> >> with
>> >> explicit init priority.
>> >>
>> >> Also prepend "sub_" before the 'I', that way regular constructors stay
>> >> lexicographically after symbols with init priority (because
>> >> ord('s') > ord('I')). gold seems to ignore the name of constructor
>> >> symbols,
>> >> and ld only looks at the symbol if it includes an init priority, which
>> >> this
>> >> patch doesn't change.
>> >>
>> >> Before: __GLOBAL_I_a
>> >> Now: __GLOBAL_sub_I_myfile.cc
>> >>
>> >> Modified:
>> >> cfe/trunk/lib/CodeGen/CGDeclCXX.cpp
>> >> cfe/trunk/test/CodeGenCXX/deferred-global-init.cpp
>> >> cfe/trunk/test/CodeGenCXX/global-init.cpp
>> >> cfe/trunk/test/CodeGenCXX/globalinit-loc.cpp
>> >> cfe/trunk/test/CodeGenCXX/init-priority-attr.cpp
>> >> cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp
>> >> cfe/trunk/test/CodeGenCXX/runtimecc.cpp
>> >>
>> >> cfe/trunk/test/CodeGenCXX/static-member-variable-explicit-specialization.cpp
>> >> cfe/trunk/test/CodeGenObjCXX/arc-globals.mm
>> >>
>> >> Modified: cfe/trunk/lib/CodeGen/CGDeclCXX.cpp
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGDeclCXX.cpp?rev=208128&r1=208127&r2=208128&view=diff
>> >>
>> >> ==============================================================================
>> >> --- cfe/trunk/lib/CodeGen/CGDeclCXX.cpp (original)
>> >> +++ cfe/trunk/lib/CodeGen/CGDeclCXX.cpp Tue May 6 15:32:45 2014
>> >> @@ -17,6 +17,7 @@
>> >> #include "clang/Frontend/CodeGenOptions.h"
>> >> #include "llvm/ADT/StringExtras.h"
>> >> #include "llvm/IR/Intrinsics.h"
>> >> +#include "llvm/Support/Path.h"
>> >>
>> >> using namespace clang;
>> >> using namespace CodeGen;
>> >> @@ -362,7 +363,7 @@ CodeGenModule::EmitCXXGlobalInitFunc() {
>> >> // Compute the function suffix from priority. Prepend with
>> >> zeroes to make
>> >> // sure the function names are also ordered as priorities.
>> >> std::string PrioritySuffix = llvm::utostr(Priority);
>> >> - // Priority is always <= 65535 (enforced by sema)..
>> >> + // Priority is always <= 65535 (enforced by sema).
>> >> PrioritySuffix = std::string(6-PrioritySuffix.size(),
>> >> '0')+PrioritySuffix;
>> >> llvm::Function *Fn =
>> >> CreateGlobalInitOrDestructFunction(*this, FTy,
>> >> @@ -376,8 +377,20 @@ CodeGenModule::EmitCXXGlobalInitFunc() {
>> >> }
>> >> }
>> >>
>> >> - llvm::Function *Fn =
>> >> - CreateGlobalInitOrDestructFunction(*this, FTy, "_GLOBAL__I_a");
>> >> + // Include the filename in the symbol name. Including "sub_" matches
>> >> gcc and
>> >> + // makes sure these symbols appear lexicographically behind the
>> >> symbols with
>> >> + // priority emitted above.
>> >> + SourceManager &SM = Context.getSourceManager();
>> >> + SmallString<128> FileName(llvm::sys::path::filename(
>> >> + SM.getFileEntryForID(SM.getMainFileID())->getName()));
>> >> + for (size_t i = 0; i < FileName.size(); ++i) {
>> >> + // Replace everything that's not [a-zA-Z0-9._] with a _. This set
>> >> happens
>> >> + // to be the set of C preprocessing numbers.
>> >> + if (!isPreprocessingNumberBody(FileName[i]))
>> >> + FileName[i] = '_';
>> >> + }
>> >> + llvm::Function *Fn = CreateGlobalInitOrDestructFunction(
>> >> + *this, FTy, llvm::Twine("_GLOBAL__sub_I_", FileName));
>> >>
>> >> CodeGenFunction(*this).GenerateCXXGlobalInitFunc(Fn,
>> >> CXXGlobalInits);
>> >> AddGlobalCtor(Fn);
>> >>
>> >> Modified: cfe/trunk/test/CodeGenCXX/deferred-global-init.cpp
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/deferred-global-init.cpp?rev=208128&r1=208127&r2=208128&view=diff
>> >>
>> >> ==============================================================================
>> >> --- cfe/trunk/test/CodeGenCXX/deferred-global-init.cpp (original)
>> >> +++ cfe/trunk/test/CodeGenCXX/deferred-global-init.cpp Tue May 6
>> >> 15:32:45 2014
>> >> @@ -11,6 +11,6 @@ void* bar() { return a; }
>> >> // CHECK: load i8** @foo
>> >> // CHECK: ret void
>> >>
>> >> -// CHECK-LABEL: define internal void @_GLOBAL__I_a
>> >> +// CHECK-LABEL: define internal void
>> >> @_GLOBAL__sub_I_deferred_global_init.cpp
>> >> // CHECK: call void @__cxx_global_var_init()
>> >> // CHECK: ret void
>> >>
>> >> Modified: cfe/trunk/test/CodeGenCXX/global-init.cpp
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/global-init.cpp?rev=208128&r1=208127&r2=208128&view=diff
>> >>
>> >> ==============================================================================
>> >> --- cfe/trunk/test/CodeGenCXX/global-init.cpp (original)
>> >> +++ cfe/trunk/test/CodeGenCXX/global-init.cpp Tue May 6 15:32:45 2014
>> >> @@ -195,11 +195,11 @@ namespace test7 {
>> >> // CHECK-NEXT: sub
>> >> // CHECK-NEXT: store i32 {{.*}}, i32* @_ZN5test1L1yE
>> >>
>> >> -// CHECK: define internal void @_GLOBAL__I_a() section
>> >> "__TEXT,__StaticInit,regular,pure_instructions" {
>> >> +// CHECK: define internal void @_GLOBAL__sub_I_global_init.cpp()
>> >> section "__TEXT,__StaticInit,regular,pure_instructions" {
>> >> // CHECK: call void [[TEST1_Y_INIT]]
>> >> // CHECK: call void [[TEST1_Z_INIT]]
>> >>
>> >> // rdar://problem/8090834: this should be nounwind
>> >> -// CHECK-NOEXC: define internal void @_GLOBAL__I_a() [[NUW:#[0-9]+]]
>> >> section "__TEXT,__StaticInit,regular,pure_instructions" {
>> >> +// CHECK-NOEXC: define internal void @_GLOBAL__sub_I_global_init.cpp()
>> >> [[NUW:#[0-9]+]] section "__TEXT,__StaticInit,regular,pure_instructions" {
>> >>
>> >> // CHECK-NOEXC: attributes [[NUW]] = { nounwind }
>> >>
>> >> Modified: cfe/trunk/test/CodeGenCXX/globalinit-loc.cpp
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/globalinit-loc.cpp?rev=208128&r1=208127&r2=208128&view=diff
>> >>
>> >> ==============================================================================
>> >> --- cfe/trunk/test/CodeGenCXX/globalinit-loc.cpp (original)
>> >> +++ cfe/trunk/test/CodeGenCXX/globalinit-loc.cpp Tue May 6 15:32:45
>> >> 2014
>> >> @@ -4,9 +4,9 @@
>> >> // Verify that the global init helper function does not get associated
>> >> // with any source location.
>> >> //
>> >> -// CHECK: define internal void @_GLOBAL__I_a
>> >> +// CHECK: define internal void @_GLOBAL__sub_I_globalinit_loc.cpp
>> >> // CHECK: !dbg ![[DBG:.*]]
>> >> -// CHECK: "_GLOBAL__I_a", i32 0, {{.*}}, i32 0} ; [ DW_TAG_subprogram
>> >> ] [line 0] [local] [def]
>> >> +// CHECK: "_GLOBAL__sub_I_globalinit_loc.cpp", i32 0, {{.*}}, i32 0} ;
>> >> [ DW_TAG_subprogram ] [line 0] [local] [def]
>> >> // CHECK: ![[DBG]] = metadata !{i32 0, i32 0,
>> >> # 99 "someheader.h"
>> >> class A {
>> >>
>> >> Modified: cfe/trunk/test/CodeGenCXX/init-priority-attr.cpp
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/init-priority-attr.cpp?rev=208128&r1=208127&r2=208128&view=diff
>> >>
>> >> ==============================================================================
>> >> --- cfe/trunk/test/CodeGenCXX/init-priority-attr.cpp (original)
>> >> +++ cfe/trunk/test/CodeGenCXX/init-priority-attr.cpp Tue May 6
>> >> 15:32:45 2014
>> >> @@ -27,7 +27,7 @@ public:
>> >>
>> >> A C::a = A();
>> >>
>> >> -// CHECK: @llvm.global_ctors = appending global [3 x { i32, void ()*
>> >> }] [{ i32, void ()* } { i32 200, void ()* @_GLOBAL__I_000200 }, { i32, void
>> >> ()* } { i32 300, void ()* @_GLOBAL__I_000300 }, { i32, void ()* } { i32
>> >> 65535, void ()* @_GLOBAL__I_a }]
>> >> +// CHECK: @llvm.global_ctors = appending global [3 x { i32, void ()*
>> >> }] [{ i32, void ()* } { i32 200, void ()* @_GLOBAL__I_000200 }, { i32, void
>> >> ()* } { i32 300, void ()* @_GLOBAL__I_000300 }, { i32, void ()* } { i32
>> >> 65535, void ()* @_GLOBAL__sub_I_init_priority_attr.cpp }]
>> >>
>> >> // CHECK: _GLOBAL__I_000200()
>> >> // CHECK: _Z3fooi(i32 3)
>> >> @@ -38,7 +38,7 @@ A C::a = A();
>> >> // CHECK-NEXT: _Z3fooi(i32 1)
>> >> // CHECK-NEXT: ret void
>> >>
>> >> -// CHECK: _GLOBAL__I_a()
>> >> +// CHECK: _GLOBAL__sub_I_init_priority_attr.cpp()
>> >> // CHECK: _Z3fooi(i32 1)
>> >> // CHECK-NEXT: _Z3fooi(i32 4)
>> >> // CHECK-NEXT: ret void
>> >>
>> >> Modified:
>> >> cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp?rev=208128&r1=208127&r2=208128&view=diff
>> >>
>> >> ==============================================================================
>> >> --- cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp
>> >> (original)
>> >> +++ cfe/trunk/test/CodeGenCXX/microsoft-abi-static-initializers.cpp Tue
>> >> May 6 15:32:45 2014
>> >> @@ -2,7 +2,7 @@
>> >>
>> >> // CHECK: @llvm.global_ctors = appending global [2 x { i32, void ()*
>> >> }]
>> >> // CHECK: [{ i32, void ()* } { i32 65535, void ()*
>> >> @"\01??__Efoo@?$B at H@@2VA@@A at YAXXZ"
>> >> -// CHECK: { i32, void ()* } { i32 65535, void ()* @_GLOBAL__I_a }]
>> >> +// CHECK: { i32, void ()* } { i32 65535, void ()*
>> >> @_GLOBAL__sub_I_microsoft_abi_static_initializers.cpp }]
>> >>
>> >> struct S {
>> >> S();
>> >> @@ -160,7 +160,7 @@ void force_usage() {
>> >> // CHECK: call x86_thiscallcc void @"\01??1A@@QAE at XZ"{{.*}}foo
>> >> // CHECK: ret void
>> >>
>> >> -// CHECK: define internal void @_GLOBAL__I_a() [[NUW]] {
>> >> +// CHECK: define internal void
>> >> @_GLOBAL__sub_I_microsoft_abi_static_initializers.cpp() [[NUW]] {
>> >> // CHECK: call void @"\01??__Es@@YAXXZ"()
>> >> // CHECK: ret void
>> >>
>> >>
>> >> Modified: cfe/trunk/test/CodeGenCXX/runtimecc.cpp
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/runtimecc.cpp?rev=208128&r1=208127&r2=208128&view=diff
>> >>
>> >> ==============================================================================
>> >> --- cfe/trunk/test/CodeGenCXX/runtimecc.cpp (original)
>> >> +++ cfe/trunk/test/CodeGenCXX/runtimecc.cpp Tue May 6 15:32:45 2014
>> >> @@ -45,7 +45,7 @@ namespace test1 {
>> >>
>> >> // CHECK: declare arm_aapcscc void @__cxa_throw(i8*, i8*, i8*)
>> >>
>> >> -// CHECK-LABEL: define internal arm_aapcscc void @_GLOBAL__I_a()
>> >> +// CHECK-LABEL: define internal arm_aapcscc void
>> >> @_GLOBAL__sub_I_runtimecc.cpp()
>> >> // CHECK: call arm_aapcscc void @__cxx_global_var_init()
>> >>
>> >>
>> >>
>> >> Modified:
>> >> cfe/trunk/test/CodeGenCXX/static-member-variable-explicit-specialization.cpp
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/static-member-variable-explicit-specialization.cpp?rev=208128&r1=208127&r2=208128&view=diff
>> >>
>> >> ==============================================================================
>> >> ---
>> >> cfe/trunk/test/CodeGenCXX/static-member-variable-explicit-specialization.cpp
>> >> (original)
>> >> +++
>> >> cfe/trunk/test/CodeGenCXX/static-member-variable-explicit-specialization.cpp
>> >> Tue May 6 15:32:45 2014
>> >> @@ -19,14 +19,14 @@ template<> int A<bool>::a = 10;
>> >> // CHECK: { i32, void ()* } { i32 65535, void ()* @[[unordered4:[^
>> >> ]*]] },
>> >> // CHECK: { i32, void ()* } { i32 65535, void ()* @[[unordered5:[^
>> >> ]*]] },
>> >> // CHECK: { i32, void ()* } { i32 65535, void ()* @[[unordered6:[^
>> >> ]*]] },
>> >> -// CHECK: { i32, void ()* } { i32 65535, void ()* @_GLOBAL__I_a }]
>> >> +// CHECK: { i32, void ()* } { i32 65535, void ()*
>> >> @_GLOBAL__sub_I_static_member_variable_explicit_specialization.cpp }]
>> >>
>> >> template int A<short>::a; // Unordered
>> >> int b = foo();
>> >> int c = foo();
>> >> int d = A<void>::a; // Unordered
>> >>
>> >> -// An explicit specialization is ordered, and goes in __GLOBAL_I_a.
>> >> +// An explicit specialization is ordered, and goes in
>> >> __GLOBAL_sub_I_static_member_variable_explicit_specialization.cpp.
>> >> template<> struct A<int> { static int a; };
>> >> int A<int>::a = foo();
>> >>
>> >> @@ -82,7 +82,7 @@ template int b::i<int>;
>> >> // CHECK: store {{.*}} @_Z1xIcE
>> >> // CHECK: ret
>> >>
>> >> -// CHECK: define internal void @_GLOBAL__I_a()
>> >> +// CHECK: define internal void
>> >> @_GLOBAL__sub_I_static_member_variable_explicit_specialization.cpp()
>> >> // We call unique stubs for every ordered dynamic initializer in the
>> >> TU.
>> >> // CHECK: call
>> >> // CHECK: call
>> >>
>> >> Modified: cfe/trunk/test/CodeGenObjCXX/arc-globals.mm
>> >> URL:
>> >> http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenObjCXX/arc-globals.mm?rev=208128&r1=208127&r2=208128&view=diff
>> >>
>> >> ==============================================================================
>> >> --- cfe/trunk/test/CodeGenObjCXX/arc-globals.mm (original)
>> >> +++ cfe/trunk/test/CodeGenObjCXX/arc-globals.mm Tue May 6 15:32:45
>> >> 2014
>> >> @@ -19,7 +19,7 @@ id global_obj = getObject();
>> >> // CHECK-NEXT: ret void
>> >> id global_obj2 = getObject();
>> >>
>> >> -// CHECK-LABEL: define internal void @_GLOBAL__I_a
>> >> +// CHECK-LABEL: define internal void @_GLOBAL__sub_I_arc_globals.mm
>> >> // CHECK: call i8* @objc_autoreleasePoolPush()
>> >> // CHECK-NEXT: call void @__cxx_global_var_init
>> >> // CHECK-NEXT: call void @__cxx_global_var_init1
>> >>
>> >>
>> >> _______________________________________________
>> >> cfe-commits mailing list
>> >> cfe-commits at cs.uiuc.edu
>> >> http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
>
>
>
>
> --
> Alexey Samsonov, Mountain View, CA
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